// Copyright 2011 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <cmath>

#include "src/base/logging.h"
#include "src/utils.h"

#include "src/dtoa.h"

#include "src/bignum-dtoa.h"
#include "src/double.h"
#include "src/fast-dtoa.h"
#include "src/fixed-dtoa.h"

namespace v8 {
namespace internal {

    static BignumDtoaMode DtoaToBignumDtoaMode(DtoaMode dtoa_mode)
    {
        switch (dtoa_mode) {
        case DTOA_SHORTEST:
            return BIGNUM_DTOA_SHORTEST;
        case DTOA_FIXED:
            return BIGNUM_DTOA_FIXED;
        case DTOA_PRECISION:
            return BIGNUM_DTOA_PRECISION;
        default:
            UNREACHABLE();
        }
    }

    void DoubleToAscii(double v, DtoaMode mode, int requested_digits,
        Vector<char> buffer, int* sign, int* length, int* point)
    {
        DCHECK(!Double(v).IsSpecial());
        DCHECK(mode == DTOA_SHORTEST || requested_digits >= 0);

        if (Double(v).Sign() < 0) {
            *sign = 1;
            v = -v;
        } else {
            *sign = 0;
        }

        if (v == 0) {
            buffer[0] = '0';
            buffer[1] = '\0';
            *length = 1;
            *point = 1;
            return;
        }

        if (mode == DTOA_PRECISION && requested_digits == 0) {
            buffer[0] = '\0';
            *length = 0;
            return;
        }

        bool fast_worked;
        switch (mode) {
        case DTOA_SHORTEST:
            fast_worked = FastDtoa(v, FAST_DTOA_SHORTEST, 0, buffer, length, point);
            break;
        case DTOA_FIXED:
            fast_worked = FastFixedDtoa(v, requested_digits, buffer, length, point);
            break;
        case DTOA_PRECISION:
            fast_worked = FastDtoa(v, FAST_DTOA_PRECISION, requested_digits,
                buffer, length, point);
            break;
        default:
            UNREACHABLE();
        }
        if (fast_worked)
            return;

        // If the fast dtoa didn't succeed use the slower bignum version.
        BignumDtoaMode bignum_mode = DtoaToBignumDtoaMode(mode);
        BignumDtoa(v, bignum_mode, requested_digits, buffer, length, point);
        buffer[*length] = '\0';
    }

} // namespace internal
} // namespace v8
